package demo2;

public class Text2 {
    public class MyLinkedList {

        static class ListNode {
            public int val;
            public ListNode prev;
            public ListNode next;

            public ListNode(int val) {
                this.val = val;
            }
        }

        //标记头
        public ListNode head;
        //标记尾
        public ListNode last;

        //头插法
        public void addFirst(int data){
            ListNode node = new ListNode(data);
            if(head == null) {
                head = node;
                last = node;
            }else {
                node.next = head;
                head.prev = node;
                head = node;
            }
        }
        //尾插法
        public void addLast(int data){
            ListNode node = new ListNode(data);
            if(head == null) {
                head = node;
                last = node;
            }else {
                last.next = node;
                node.prev = last;
                last = node;
            }
        }
        //任意位置插入,第一个数据节点为0号下标
        public void addIndex(int index,int data){
            int size = size();
            if(index < 0 || index > size) {
                System.out.println("下标位置不合法："+index);
                return;
            }
            if(index == 0) {
                addFirst(data);
                return;
            }
            if(index == size) {
                addLast(data);
                return;
            }
            ListNode node = new ListNode(data);
            ListNode cur = search(index);
            node.next = cur;
            cur.prev.next = node;
            node.prev = cur.prev;
            cur.prev = node;
        }

        private ListNode search(int index) {
            ListNode cur = head;
            while (index != 0) {
                cur = cur.next;
                index--;
            }
            return cur;
        }

        //查找是否包含关键字key是否在单链表当中
        public boolean contains(int key){
            ListNode cur = head;
            while (cur != null) {
                if(cur.val == key) {
                    return true;
                }
                cur = cur.next;
            }
            return false;
        }
        //删除第一次出现关键字为key的节点
        public void remove(int key){
            ListNode cur = head;
            while (cur != null) {
                if(cur.val == key) {
                    if(cur == head) {
                        //删除头节点
                        head = head.next;
                        if(head == null) {
                            //只有一个节点的情况下
                            last = null;
                        }else {
                            head.prev = null;
                        }
                    }else {
                        //删除中间和尾巴
                        if(cur.next == null) {
                            //尾巴
                            cur.prev.next = cur.next;
                            last = last.prev;
                        }else {
                            cur.prev.next = cur.next;
                            cur.next.prev = cur.prev;
                        }
                    }
                    return;
                }
                cur = cur.next;
            }
        }

        //删除所有值为key的节点
        public void removeAllKey(int key){
            ListNode cur = head;
            while (cur != null) {
                if(cur.val == key) {
                    if(cur == head) {
                        //删除头节点
                        head = head.next;
                        if(head == null) {
                            //只有一个节点的情况下
                            last = null;
                        }else {
                            head.prev = null;
                        }
                    }else {
                        //删除中间和尾巴
                        if(cur.next == null) {
                            //尾巴
                            cur.prev.next = cur.next;
                            last = last.prev;
                        }else {
                            cur.prev.next = cur.next;
                            cur.next.prev = cur.prev;
                        }
                    }
                    //return;
                }
                cur = cur.next;
            }
        }

        //得到单链表的长度
        public int size(){
            ListNode cur = head;
            int count = 0;
            while (cur != null) {
                count++;
                cur = cur.next;
            }
            return count;
        }
        public void display(){
            ListNode cur = head;
            while (cur != null) {
                System.out.print(cur.val+" ");
                cur = cur.next;
            }
            System.out.println();
        }

        public void clear(){
            ListNode cur = head;
            while (cur != null) {
                ListNode curN = cur.next;
                //cur.val = null;
                cur.prev = null;
                cur.next = null;
                cur = curN;
            }
            head = null;
            last = null;
        }
    }public class MyLinkedList1 {

        static class ListNode {
            public int val;
            public ListNode prev;
            public ListNode next;

            public ListNode(int val) {
                this.val = val;
            }
        }

        //标记头
        public ListNode head;
        //标记尾
        public ListNode last;

        //头插法
        public void addFirst(int data){
            ListNode node = new ListNode(data);
            if(head == null) {
                head = node;
                last = node;
            }else {
                node.next = head;
                head.prev = node;
                head = node;
            }
        }
        //尾插法
        public void addLast(int data){
            ListNode node = new ListNode(data);
            if(head == null) {
                head = node;
                last = node;
            }else {
                last.next = node;
                node.prev = last;
                last = node;
            }
        }
        //任意位置插入,第一个数据节点为0号下标
        public void addIndex(int index,int data){
            int size = size();
            if(index < 0 || index > size) {
                System.out.println("下标位置不合法："+index);
                return;
            }
            if(index == 0) {
                addFirst(data);
                return;
            }
            if(index == size) {
                addLast(data);
                return;
            }
            ListNode node = new ListNode(data);
            ListNode cur = search(index);
            node.next = cur;
            cur.prev.next = node;
            node.prev = cur.prev;
            cur.prev = node;
        }

        private ListNode search(int index) {
            ListNode cur = head;
            while (index != 0) {
                cur = cur.next;
                index--;
            }
            return cur;
        }

        //查找是否包含关键字key是否在单链表当中
        public boolean contains(int key){
            ListNode cur = head;
            while (cur != null) {
                if(cur.val == key) {
                    return true;
                }
                cur = cur.next;
            }
            return false;
        }
        //删除第一次出现关键字为key的节点
        public void remove(int key){
            ListNode cur = head;
            while (cur != null) {
                if(cur.val == key) {
                    if(cur == head) {
                        //删除头节点
                        head = head.next;
                        if(head == null) {
                            //只有一个节点的情况下
                            last = null;
                        }else {
                            head.prev = null;
                        }
                    }else {
                        //删除中间和尾巴
                        if(cur.next == null) {
                            //尾巴
                            cur.prev.next = cur.next;
                            last = last.prev;
                        }else {
                            cur.prev.next = cur.next;
                            cur.next.prev = cur.prev;
                        }
                    }
                    return;
                }
                cur = cur.next;
            }
        }

        //删除所有值为key的节点
        public void removeAllKey(int key){
            ListNode cur = head;
            while (cur != null) {
                if(cur.val == key) {
                    if(cur == head) {
                        //删除头节点
                        head = head.next;
                        if(head == null) {
                            //只有一个节点的情况下
                            last = null;
                        }else {
                            head.prev = null;
                        }
                    }else {
                        //删除中间和尾巴
                        if(cur.next == null) {
                            //尾巴
                            cur.prev.next = cur.next;
                            last = last.prev;
                        }else {
                            cur.prev.next = cur.next;
                            cur.next.prev = cur.prev;
                        }
                    }
                    //return;
                }
                cur = cur.next;
            }
        }

        //得到单链表的长度
        public int size(){
            ListNode cur = head;
            int count = 0;
            while (cur != null) {
                count++;
                cur = cur.next;
            }
            return count;
        }
        public void display(){
            ListNode cur = head;
            while (cur != null) {
                System.out.print(cur.val+" ");
                cur = cur.next;
            }
            System.out.println();
        }

        public void clear(){
            ListNode cur = head;
            while (cur != null) {
                ListNode curN = cur.next;
                //cur.val = null;
                cur.prev = null;
                cur.next = null;
                cur = curN;
            }
            head = null;
            last = null;
        }
    }
}
